2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
12 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
13 * Copyright (c) 2013, 2014 The FreeBSD Foundation
15 * Portions of this software were developed by Konstantin Belousov
16 * under sponsorship from the FreeBSD Foundation.
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution.
26 * 3. Neither the name of the University nor the names of its contributors
27 * may be used to endorse or promote products derived from this software
28 * without specific prior written permission.
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
48 #include "opt_hwpmc_hooks.h"
50 #include <sys/param.h>
51 #include <sys/systm.h>
54 #include <sys/fcntl.h>
61 #include <sys/limits.h>
64 #include <sys/mount.h>
65 #include <sys/mutex.h>
66 #include <sys/namei.h>
67 #include <sys/vnode.h>
70 #include <sys/filio.h>
71 #include <sys/resourcevar.h>
72 #include <sys/rwlock.h>
74 #include <sys/sysctl.h>
75 #include <sys/ttycom.h>
77 #include <sys/syslog.h>
78 #include <sys/unistd.h>
81 #include <security/audit/audit.h>
82 #include <security/mac/mac_framework.h>
85 #include <vm/vm_extern.h>
87 #include <vm/vm_map.h>
88 #include <vm/vm_object.h>
89 #include <vm/vm_page.h>
90 #include <vm/vm_pager.h>
93 #include <sys/pmckern.h>
96 static fo_rdwr_t vn_read;
97 static fo_rdwr_t vn_write;
98 static fo_rdwr_t vn_io_fault;
99 static fo_truncate_t vn_truncate;
100 static fo_ioctl_t vn_ioctl;
101 static fo_poll_t vn_poll;
102 static fo_kqfilter_t vn_kqfilter;
103 static fo_stat_t vn_statfile;
104 static fo_close_t vn_closefile;
105 static fo_mmap_t vn_mmap;
107 struct fileops vnops = {
108 .fo_read = vn_io_fault,
109 .fo_write = vn_io_fault,
110 .fo_truncate = vn_truncate,
111 .fo_ioctl = vn_ioctl,
113 .fo_kqfilter = vn_kqfilter,
114 .fo_stat = vn_statfile,
115 .fo_close = vn_closefile,
116 .fo_chmod = vn_chmod,
117 .fo_chown = vn_chown,
118 .fo_sendfile = vn_sendfile,
120 .fo_fill_kinfo = vn_fill_kinfo,
122 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
125 static const int io_hold_cnt = 16;
126 static int vn_io_fault_enable = 1;
127 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW,
128 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
129 static int vn_io_fault_prefault = 0;
130 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW,
131 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
132 static u_long vn_io_faults_cnt;
133 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
134 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
137 * Returns true if vn_io_fault mode of handling the i/o request should
141 do_vn_io_fault(struct vnode *vp, struct uio *uio)
145 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
146 (mp = vp->v_mount) != NULL &&
147 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
151 * Structure used to pass arguments to vn_io_fault1(), to do either
152 * file- or vnode-based I/O calls.
154 struct vn_io_fault_args {
162 struct fop_args_tag {
166 struct vop_args_tag {
172 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
173 struct vn_io_fault_args *args, struct thread *td);
176 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp)
178 struct thread *td = ndp->ni_cnd.cn_thread;
180 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
184 * Common code for vnode open operations via a name lookup.
185 * Lookup the vnode and invoke VOP_CREATE if needed.
186 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
188 * Note that this does NOT free nameidata for the successful case,
189 * due to the NDINIT being done elsewhere.
192 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
193 struct ucred *cred, struct file *fp)
197 struct thread *td = ndp->ni_cnd.cn_thread;
199 struct vattr *vap = &vat;
204 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
205 O_EXCL | O_DIRECTORY))
207 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
208 ndp->ni_cnd.cn_nameiop = CREATE;
210 * Set NOCACHE to avoid flushing the cache when
211 * rolling in many files at once.
213 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE;
214 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
215 ndp->ni_cnd.cn_flags |= FOLLOW;
216 if ((fmode & O_BENEATH) != 0)
217 ndp->ni_cnd.cn_flags |= BENEATH;
218 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
219 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
220 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
221 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
223 if ((error = namei(ndp)) != 0)
225 if (ndp->ni_vp == NULL) {
228 vap->va_mode = cmode;
230 vap->va_vaflags |= VA_EXCLUSIVE;
231 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
232 NDFREE(ndp, NDF_ONLY_PNBUF);
234 if ((error = vn_start_write(NULL, &mp,
235 V_XSLEEP | PCATCH)) != 0)
239 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
240 ndp->ni_cnd.cn_flags |= MAKEENTRY;
242 error = mac_vnode_check_create(cred, ndp->ni_dvp,
246 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
249 vn_finished_write(mp);
251 NDFREE(ndp, NDF_ONLY_PNBUF);
257 if (ndp->ni_dvp == ndp->ni_vp)
263 if (fmode & O_EXCL) {
267 if (vp->v_type == VDIR) {
274 ndp->ni_cnd.cn_nameiop = LOOKUP;
275 ndp->ni_cnd.cn_flags = ISOPEN |
276 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF;
277 if (!(fmode & FWRITE))
278 ndp->ni_cnd.cn_flags |= LOCKSHARED;
279 if ((fmode & O_BENEATH) != 0)
280 ndp->ni_cnd.cn_flags |= BENEATH;
281 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
282 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
283 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
284 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
285 if ((error = namei(ndp)) != 0)
289 error = vn_open_vnode(vp, fmode, cred, td, fp);
295 NDFREE(ndp, NDF_ONLY_PNBUF);
303 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp)
306 int error, lock_flags, type;
308 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock");
309 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0)
311 KASSERT(fp != NULL, ("open with flock requires fp"));
312 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE)
315 lock_flags = VOP_ISLOCKED(vp);
318 lf.l_whence = SEEK_SET;
321 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK;
323 if ((fmode & FNONBLOCK) == 0)
325 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
327 fp->f_flag |= FHASLOCK;
329 vn_lock(vp, lock_flags | LK_RETRY);
330 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
336 * Common code for vnode open operations once a vnode is located.
337 * Check permissions, and call the VOP_OPEN routine.
340 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
341 struct thread *td, struct file *fp)
346 if (vp->v_type == VLNK)
348 if (vp->v_type == VSOCK)
350 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
353 if (fmode & (FWRITE | O_TRUNC)) {
354 if (vp->v_type == VDIR)
362 if ((fmode & O_APPEND) && (fmode & FWRITE))
367 if (fmode & O_VERIFY)
369 error = mac_vnode_check_open(cred, vp, accmode);
373 accmode &= ~(VCREAT | VVERIFY);
375 if ((fmode & O_CREAT) == 0 && accmode != 0) {
376 error = VOP_ACCESS(vp, accmode, cred, td);
380 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
381 vn_lock(vp, LK_UPGRADE | LK_RETRY);
382 error = VOP_OPEN(vp, fmode, cred, td, fp);
386 error = vn_open_vnode_advlock(vp, fmode, fp);
387 if (error == 0 && (fmode & FWRITE) != 0) {
388 error = VOP_ADD_WRITECOUNT(vp, 1);
390 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
391 __func__, vp, vp->v_writecount);
396 * Error from advlock or VOP_ADD_WRITECOUNT() still requires
397 * calling VOP_CLOSE() to pair with earlier VOP_OPEN().
398 * Arrange for that by having fdrop() to use vn_closefile().
401 fp->f_flag |= FOPENFAILED;
403 if (fp->f_ops == &badfileops) {
404 fp->f_type = DTYPE_VNODE;
410 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
416 * Check for write permissions on the specified vnode.
417 * Prototype text segments cannot be written.
421 vn_writechk(struct vnode *vp)
424 ASSERT_VOP_LOCKED(vp, "vn_writechk");
426 * If there's shared text associated with
427 * the vnode, try to free it up once. If
428 * we fail, we can't allow writing.
440 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred,
441 struct thread *td, bool keep_ref)
444 int error, lock_flags;
446 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
447 MNT_EXTENDED_SHARED(vp->v_mount))
448 lock_flags = LK_SHARED;
450 lock_flags = LK_EXCLUSIVE;
452 vn_start_write(vp, &mp, V_WAIT);
453 vn_lock(vp, lock_flags | LK_RETRY);
454 AUDIT_ARG_VNODE1(vp);
455 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) {
456 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
457 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
458 __func__, vp, vp->v_writecount);
460 error = VOP_CLOSE(vp, flags, file_cred, td);
465 vn_finished_write(mp);
470 vn_close(struct vnode *vp, int flags, struct ucred *file_cred,
474 return (vn_close1(vp, flags, file_cred, td, false));
478 * Heuristic to detect sequential operation.
481 sequential_heuristic(struct uio *uio, struct file *fp)
484 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
485 if (fp->f_flag & FRDAHEAD)
486 return (fp->f_seqcount << IO_SEQSHIFT);
489 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
490 * that the first I/O is normally considered to be slightly
491 * sequential. Seeking to offset 0 doesn't change sequentiality
492 * unless previous seeks have reduced f_seqcount to 0, in which
493 * case offset 0 is not special.
495 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
496 uio->uio_offset == fp->f_nextoff) {
498 * f_seqcount is in units of fixed-size blocks so that it
499 * depends mainly on the amount of sequential I/O and not
500 * much on the number of sequential I/O's. The fixed size
501 * of 16384 is hard-coded here since it is (not quite) just
502 * a magic size that works well here. This size is more
503 * closely related to the best I/O size for real disks than
504 * to any block size used by software.
506 if (uio->uio_resid >= IO_SEQMAX * 16384)
507 fp->f_seqcount = IO_SEQMAX;
509 fp->f_seqcount += howmany(uio->uio_resid, 16384);
510 if (fp->f_seqcount > IO_SEQMAX)
511 fp->f_seqcount = IO_SEQMAX;
513 return (fp->f_seqcount << IO_SEQSHIFT);
516 /* Not sequential. Quickly draw-down sequentiality. */
517 if (fp->f_seqcount > 1)
525 * Package up an I/O request on a vnode into a uio and do it.
528 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
529 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
530 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
537 struct vn_io_fault_args args;
538 int error, lock_flags;
540 if (offset < 0 && vp->v_type != VCHR)
542 auio.uio_iov = &aiov;
544 aiov.iov_base = base;
546 auio.uio_resid = len;
547 auio.uio_offset = offset;
548 auio.uio_segflg = segflg;
553 if ((ioflg & IO_NODELOCKED) == 0) {
554 if ((ioflg & IO_RANGELOCKED) == 0) {
555 if (rw == UIO_READ) {
556 rl_cookie = vn_rangelock_rlock(vp, offset,
559 rl_cookie = vn_rangelock_wlock(vp, offset,
565 if (rw == UIO_WRITE) {
566 if (vp->v_type != VCHR &&
567 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
570 if (MNT_SHARED_WRITES(mp) ||
571 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount)))
572 lock_flags = LK_SHARED;
574 lock_flags = LK_EXCLUSIVE;
576 lock_flags = LK_SHARED;
577 vn_lock(vp, lock_flags | LK_RETRY);
581 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
583 if ((ioflg & IO_NOMACCHECK) == 0) {
585 error = mac_vnode_check_read(active_cred, file_cred,
588 error = mac_vnode_check_write(active_cred, file_cred,
593 if (file_cred != NULL)
597 if (do_vn_io_fault(vp, &auio)) {
598 args.kind = VN_IO_FAULT_VOP;
601 args.args.vop_args.vp = vp;
602 error = vn_io_fault1(vp, &auio, &args, td);
603 } else if (rw == UIO_READ) {
604 error = VOP_READ(vp, &auio, ioflg, cred);
605 } else /* if (rw == UIO_WRITE) */ {
606 error = VOP_WRITE(vp, &auio, ioflg, cred);
610 *aresid = auio.uio_resid;
612 if (auio.uio_resid && error == 0)
614 if ((ioflg & IO_NODELOCKED) == 0) {
617 vn_finished_write(mp);
620 if (rl_cookie != NULL)
621 vn_rangelock_unlock(vp, rl_cookie);
626 * Package up an I/O request on a vnode into a uio and do it. The I/O
627 * request is split up into smaller chunks and we try to avoid saturating
628 * the buffer cache while potentially holding a vnode locked, so we
629 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
630 * to give other processes a chance to lock the vnode (either other processes
631 * core'ing the same binary, or unrelated processes scanning the directory).
634 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len,
635 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred,
636 struct ucred *file_cred, size_t *aresid, struct thread *td)
645 * Force `offset' to a multiple of MAXBSIZE except possibly
646 * for the first chunk, so that filesystems only need to
647 * write full blocks except possibly for the first and last
650 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
654 if (rw != UIO_READ && vp->v_type == VREG)
657 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
658 ioflg, active_cred, file_cred, &iaresid, td);
659 len -= chunk; /* aresid calc already includes length */
663 base = (char *)base + chunk;
664 kern_yield(PRI_USER);
667 *aresid = len + iaresid;
672 foffset_lock(struct file *fp, int flags)
677 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
679 #if OFF_MAX <= LONG_MAX
681 * Caller only wants the current f_offset value. Assume that
682 * the long and shorter integer types reads are atomic.
684 if ((flags & FOF_NOLOCK) != 0)
685 return (fp->f_offset);
689 * According to McKusick the vn lock was protecting f_offset here.
690 * It is now protected by the FOFFSET_LOCKED flag.
692 mtxp = mtx_pool_find(mtxpool_sleep, fp);
694 if ((flags & FOF_NOLOCK) == 0) {
695 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
696 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
697 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
700 fp->f_vnread_flags |= FOFFSET_LOCKED;
708 foffset_unlock(struct file *fp, off_t val, int flags)
712 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
714 #if OFF_MAX <= LONG_MAX
715 if ((flags & FOF_NOLOCK) != 0) {
716 if ((flags & FOF_NOUPDATE) == 0)
718 if ((flags & FOF_NEXTOFF) != 0)
724 mtxp = mtx_pool_find(mtxpool_sleep, fp);
726 if ((flags & FOF_NOUPDATE) == 0)
728 if ((flags & FOF_NEXTOFF) != 0)
730 if ((flags & FOF_NOLOCK) == 0) {
731 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
732 ("Lost FOFFSET_LOCKED"));
733 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
734 wakeup(&fp->f_vnread_flags);
735 fp->f_vnread_flags = 0;
741 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
744 if ((flags & FOF_OFFSET) == 0)
745 uio->uio_offset = foffset_lock(fp, flags);
749 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
752 if ((flags & FOF_OFFSET) == 0)
753 foffset_unlock(fp, uio->uio_offset, flags);
757 get_advice(struct file *fp, struct uio *uio)
762 ret = POSIX_FADV_NORMAL;
763 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG)
766 mtxp = mtx_pool_find(mtxpool_sleep, fp);
768 if (fp->f_advice != NULL &&
769 uio->uio_offset >= fp->f_advice->fa_start &&
770 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
771 ret = fp->f_advice->fa_advice;
777 * File table vnode read routine.
780 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
788 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
790 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
793 if (fp->f_flag & FNONBLOCK)
795 if (fp->f_flag & O_DIRECT)
797 advice = get_advice(fp, uio);
798 vn_lock(vp, LK_SHARED | LK_RETRY);
801 case POSIX_FADV_NORMAL:
802 case POSIX_FADV_SEQUENTIAL:
803 case POSIX_FADV_NOREUSE:
804 ioflag |= sequential_heuristic(uio, fp);
806 case POSIX_FADV_RANDOM:
807 /* Disable read-ahead for random I/O. */
810 orig_offset = uio->uio_offset;
813 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
816 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
817 fp->f_nextoff = uio->uio_offset;
819 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
820 orig_offset != uio->uio_offset)
822 * Use POSIX_FADV_DONTNEED to flush pages and buffers
823 * for the backing file after a POSIX_FADV_NOREUSE
826 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
827 POSIX_FADV_DONTNEED);
832 * File table vnode write routine.
835 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
841 int error, ioflag, lock_flags;
844 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
846 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
848 if (vp->v_type == VREG)
851 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
853 if (fp->f_flag & FNONBLOCK)
855 if (fp->f_flag & O_DIRECT)
857 if ((fp->f_flag & O_FSYNC) ||
858 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
861 if (vp->v_type != VCHR &&
862 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
865 advice = get_advice(fp, uio);
867 if (MNT_SHARED_WRITES(mp) ||
868 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) {
869 lock_flags = LK_SHARED;
871 lock_flags = LK_EXCLUSIVE;
874 vn_lock(vp, lock_flags | LK_RETRY);
876 case POSIX_FADV_NORMAL:
877 case POSIX_FADV_SEQUENTIAL:
878 case POSIX_FADV_NOREUSE:
879 ioflag |= sequential_heuristic(uio, fp);
881 case POSIX_FADV_RANDOM:
882 /* XXX: Is this correct? */
885 orig_offset = uio->uio_offset;
888 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
891 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
892 fp->f_nextoff = uio->uio_offset;
894 if (vp->v_type != VCHR)
895 vn_finished_write(mp);
896 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
897 orig_offset != uio->uio_offset)
899 * Use POSIX_FADV_DONTNEED to flush pages and buffers
900 * for the backing file after a POSIX_FADV_NOREUSE
903 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
904 POSIX_FADV_DONTNEED);
910 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
911 * prevent the following deadlock:
913 * Assume that the thread A reads from the vnode vp1 into userspace
914 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
915 * currently not resident, then system ends up with the call chain
916 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
917 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
918 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
919 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
920 * backed by the pages of vnode vp1, and some page in buf2 is not
921 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
923 * To prevent the lock order reversal and deadlock, vn_io_fault() does
924 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
925 * Instead, it first tries to do the whole range i/o with pagefaults
926 * disabled. If all pages in the i/o buffer are resident and mapped,
927 * VOP will succeed (ignoring the genuine filesystem errors).
928 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
929 * i/o in chunks, with all pages in the chunk prefaulted and held
930 * using vm_fault_quick_hold_pages().
932 * Filesystems using this deadlock avoidance scheme should use the
933 * array of the held pages from uio, saved in the curthread->td_ma,
934 * instead of doing uiomove(). A helper function
935 * vn_io_fault_uiomove() converts uiomove request into
936 * uiomove_fromphys() over td_ma array.
938 * Since vnode locks do not cover the whole i/o anymore, rangelocks
939 * make the current i/o request atomic with respect to other i/os and
944 * Decode vn_io_fault_args and perform the corresponding i/o.
947 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
953 save = vm_fault_disable_pagefaults();
954 switch (args->kind) {
955 case VN_IO_FAULT_FOP:
956 error = (args->args.fop_args.doio)(args->args.fop_args.fp,
957 uio, args->cred, args->flags, td);
959 case VN_IO_FAULT_VOP:
960 if (uio->uio_rw == UIO_READ) {
961 error = VOP_READ(args->args.vop_args.vp, uio,
962 args->flags, args->cred);
963 } else if (uio->uio_rw == UIO_WRITE) {
964 error = VOP_WRITE(args->args.vop_args.vp, uio,
965 args->flags, args->cred);
969 panic("vn_io_fault_doio: unknown kind of io %d %d",
970 args->kind, uio->uio_rw);
972 vm_fault_enable_pagefaults(save);
977 vn_io_fault_touch(char *base, const struct uio *uio)
982 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1))
988 vn_io_fault_prefault_user(const struct uio *uio)
991 const struct iovec *iov;
996 KASSERT(uio->uio_segflg == UIO_USERSPACE,
997 ("vn_io_fault_prefault userspace"));
1001 resid = uio->uio_resid;
1002 base = iov->iov_base;
1005 error = vn_io_fault_touch(base, uio);
1008 if (len < PAGE_SIZE) {
1010 error = vn_io_fault_touch(base + len - 1, uio);
1015 if (++i >= uio->uio_iovcnt)
1017 iov = uio->uio_iov + i;
1018 base = iov->iov_base;
1030 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1031 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1032 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1033 * into args and call vn_io_fault1() to handle faults during the user
1034 * mode buffer accesses.
1037 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1040 vm_page_t ma[io_hold_cnt + 2];
1041 struct uio *uio_clone, short_uio;
1042 struct iovec short_iovec[1];
1043 vm_page_t *prev_td_ma;
1045 vm_offset_t addr, end;
1048 int error, cnt, saveheld, prev_td_ma_cnt;
1050 if (vn_io_fault_prefault) {
1051 error = vn_io_fault_prefault_user(uio);
1053 return (error); /* Or ignore ? */
1056 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1059 * The UFS follows IO_UNIT directive and replays back both
1060 * uio_offset and uio_resid if an error is encountered during the
1061 * operation. But, since the iovec may be already advanced,
1062 * uio is still in an inconsistent state.
1064 * Cache a copy of the original uio, which is advanced to the redo
1065 * point using UIO_NOCOPY below.
1067 uio_clone = cloneuio(uio);
1068 resid = uio->uio_resid;
1070 short_uio.uio_segflg = UIO_USERSPACE;
1071 short_uio.uio_rw = uio->uio_rw;
1072 short_uio.uio_td = uio->uio_td;
1074 error = vn_io_fault_doio(args, uio, td);
1075 if (error != EFAULT)
1078 atomic_add_long(&vn_io_faults_cnt, 1);
1079 uio_clone->uio_segflg = UIO_NOCOPY;
1080 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1081 uio_clone->uio_segflg = uio->uio_segflg;
1083 saveheld = curthread_pflags_set(TDP_UIOHELD);
1084 prev_td_ma = td->td_ma;
1085 prev_td_ma_cnt = td->td_ma_cnt;
1087 while (uio_clone->uio_resid != 0) {
1088 len = uio_clone->uio_iov->iov_len;
1090 KASSERT(uio_clone->uio_iovcnt >= 1,
1091 ("iovcnt underflow"));
1092 uio_clone->uio_iov++;
1093 uio_clone->uio_iovcnt--;
1096 if (len > io_hold_cnt * PAGE_SIZE)
1097 len = io_hold_cnt * PAGE_SIZE;
1098 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1099 end = round_page(addr + len);
1104 cnt = atop(end - trunc_page(addr));
1106 * A perfectly misaligned address and length could cause
1107 * both the start and the end of the chunk to use partial
1108 * page. +2 accounts for such a situation.
1110 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1111 addr, len, prot, ma, io_hold_cnt + 2);
1116 short_uio.uio_iov = &short_iovec[0];
1117 short_iovec[0].iov_base = (void *)addr;
1118 short_uio.uio_iovcnt = 1;
1119 short_uio.uio_resid = short_iovec[0].iov_len = len;
1120 short_uio.uio_offset = uio_clone->uio_offset;
1122 td->td_ma_cnt = cnt;
1124 error = vn_io_fault_doio(args, &short_uio, td);
1125 vm_page_unhold_pages(ma, cnt);
1126 adv = len - short_uio.uio_resid;
1128 uio_clone->uio_iov->iov_base =
1129 (char *)uio_clone->uio_iov->iov_base + adv;
1130 uio_clone->uio_iov->iov_len -= adv;
1131 uio_clone->uio_resid -= adv;
1132 uio_clone->uio_offset += adv;
1134 uio->uio_resid -= adv;
1135 uio->uio_offset += adv;
1137 if (error != 0 || adv == 0)
1140 td->td_ma = prev_td_ma;
1141 td->td_ma_cnt = prev_td_ma_cnt;
1142 curthread_pflags_restore(saveheld);
1144 free(uio_clone, M_IOV);
1149 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1150 int flags, struct thread *td)
1155 struct vn_io_fault_args args;
1158 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1160 foffset_lock_uio(fp, uio, flags);
1161 if (do_vn_io_fault(vp, uio)) {
1162 args.kind = VN_IO_FAULT_FOP;
1163 args.args.fop_args.fp = fp;
1164 args.args.fop_args.doio = doio;
1165 args.cred = active_cred;
1166 args.flags = flags | FOF_OFFSET;
1167 if (uio->uio_rw == UIO_READ) {
1168 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1169 uio->uio_offset + uio->uio_resid);
1170 } else if ((fp->f_flag & O_APPEND) != 0 ||
1171 (flags & FOF_OFFSET) == 0) {
1172 /* For appenders, punt and lock the whole range. */
1173 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1175 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1176 uio->uio_offset + uio->uio_resid);
1178 error = vn_io_fault1(vp, uio, &args, td);
1179 vn_rangelock_unlock(vp, rl_cookie);
1181 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1183 foffset_unlock_uio(fp, uio, flags);
1188 * Helper function to perform the requested uiomove operation using
1189 * the held pages for io->uio_iov[0].iov_base buffer instead of
1190 * copyin/copyout. Access to the pages with uiomove_fromphys()
1191 * instead of iov_base prevents page faults that could occur due to
1192 * pmap_collect() invalidating the mapping created by
1193 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1194 * object cleanup revoking the write access from page mappings.
1196 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1197 * instead of plain uiomove().
1200 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1202 struct uio transp_uio;
1203 struct iovec transp_iov[1];
1209 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1210 uio->uio_segflg != UIO_USERSPACE)
1211 return (uiomove(data, xfersize, uio));
1213 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1214 transp_iov[0].iov_base = data;
1215 transp_uio.uio_iov = &transp_iov[0];
1216 transp_uio.uio_iovcnt = 1;
1217 if (xfersize > uio->uio_resid)
1218 xfersize = uio->uio_resid;
1219 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1220 transp_uio.uio_offset = 0;
1221 transp_uio.uio_segflg = UIO_SYSSPACE;
1223 * Since transp_iov points to data, and td_ma page array
1224 * corresponds to original uio->uio_iov, we need to invert the
1225 * direction of the i/o operation as passed to
1226 * uiomove_fromphys().
1228 switch (uio->uio_rw) {
1230 transp_uio.uio_rw = UIO_READ;
1233 transp_uio.uio_rw = UIO_WRITE;
1236 transp_uio.uio_td = uio->uio_td;
1237 error = uiomove_fromphys(td->td_ma,
1238 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1239 xfersize, &transp_uio);
1240 adv = xfersize - transp_uio.uio_resid;
1242 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1243 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1245 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1247 td->td_ma_cnt -= pgadv;
1248 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1249 uio->uio_iov->iov_len -= adv;
1250 uio->uio_resid -= adv;
1251 uio->uio_offset += adv;
1256 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1260 vm_offset_t iov_base;
1264 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1265 uio->uio_segflg != UIO_USERSPACE)
1266 return (uiomove_fromphys(ma, offset, xfersize, uio));
1268 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1269 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1270 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1271 switch (uio->uio_rw) {
1273 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1277 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1281 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1283 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1285 td->td_ma_cnt -= pgadv;
1286 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1287 uio->uio_iov->iov_len -= cnt;
1288 uio->uio_resid -= cnt;
1289 uio->uio_offset += cnt;
1295 * File table truncate routine.
1298 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1309 * Lock the whole range for truncation. Otherwise split i/o
1310 * might happen partly before and partly after the truncation.
1312 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1313 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1316 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1317 AUDIT_ARG_VNODE1(vp);
1318 if (vp->v_type == VDIR) {
1323 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1327 error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0,
1331 vn_finished_write(mp);
1333 vn_rangelock_unlock(vp, rl_cookie);
1338 * Truncate a file that is already locked.
1341 vn_truncate_locked(struct vnode *vp, off_t length, bool sync,
1347 error = VOP_ADD_WRITECOUNT(vp, 1);
1350 vattr.va_size = length;
1352 vattr.va_vaflags |= VA_SYNC;
1353 error = VOP_SETATTR(vp, &vattr, cred);
1354 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
1360 * File table vnode stat routine.
1363 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred,
1366 struct vnode *vp = fp->f_vnode;
1369 vn_lock(vp, LK_SHARED | LK_RETRY);
1370 error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
1377 * Stat a vnode; implementation for the stat syscall
1380 vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred,
1381 struct ucred *file_cred, struct thread *td)
1388 AUDIT_ARG_VNODE1(vp);
1390 error = mac_vnode_check_stat(active_cred, file_cred, vp);
1398 * Initialize defaults for new and unusual fields, so that file
1399 * systems which don't support these fields don't need to know
1402 vap->va_birthtime.tv_sec = -1;
1403 vap->va_birthtime.tv_nsec = 0;
1404 vap->va_fsid = VNOVAL;
1405 vap->va_rdev = NODEV;
1407 error = VOP_GETATTR(vp, vap, active_cred);
1412 * Zero the spare stat fields
1414 bzero(sb, sizeof *sb);
1417 * Copy from vattr table
1419 if (vap->va_fsid != VNOVAL)
1420 sb->st_dev = vap->va_fsid;
1422 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
1423 sb->st_ino = vap->va_fileid;
1424 mode = vap->va_mode;
1425 switch (vap->va_type) {
1451 sb->st_nlink = vap->va_nlink;
1452 sb->st_uid = vap->va_uid;
1453 sb->st_gid = vap->va_gid;
1454 sb->st_rdev = vap->va_rdev;
1455 if (vap->va_size > OFF_MAX)
1457 sb->st_size = vap->va_size;
1458 sb->st_atim = vap->va_atime;
1459 sb->st_mtim = vap->va_mtime;
1460 sb->st_ctim = vap->va_ctime;
1461 sb->st_birthtim = vap->va_birthtime;
1464 * According to www.opengroup.org, the meaning of st_blksize is
1465 * "a filesystem-specific preferred I/O block size for this
1466 * object. In some filesystem types, this may vary from file
1468 * Use miminum/default of PAGE_SIZE (e.g. for VCHR).
1471 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize);
1473 sb->st_flags = vap->va_flags;
1474 if (priv_check(td, PRIV_VFS_GENERATION))
1477 sb->st_gen = vap->va_gen;
1479 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
1484 * File table vnode ioctl routine.
1487 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
1492 struct fiobmap2_arg *bmarg;
1496 switch (vp->v_type) {
1501 vn_lock(vp, LK_SHARED | LK_RETRY);
1502 error = VOP_GETATTR(vp, &vattr, active_cred);
1505 *(int *)data = vattr.va_size - fp->f_offset;
1508 bmarg = (struct fiobmap2_arg *)data;
1509 vn_lock(vp, LK_SHARED | LK_RETRY);
1511 error = mac_vnode_check_read(active_cred, fp->f_cred,
1515 error = VOP_BMAP(vp, bmarg->bn, NULL,
1516 &bmarg->bn, &bmarg->runp, &bmarg->runb);
1523 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1528 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1536 * File table vnode poll routine.
1539 vn_poll(struct file *fp, int events, struct ucred *active_cred,
1547 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1548 AUDIT_ARG_VNODE1(vp);
1549 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1554 error = VOP_POLL(vp, events, fp->f_cred, td);
1559 * Acquire the requested lock and then check for validity. LK_RETRY
1560 * permits vn_lock to return doomed vnodes.
1563 _vn_lock(struct vnode *vp, int flags, char *file, int line)
1567 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1568 ("vn_lock: no locktype"));
1569 VNASSERT(vp->v_holdcnt != 0, vp, ("vn_lock: zero hold count"));
1571 error = VOP_LOCK1(vp, flags, file, line);
1572 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */
1573 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1574 ("vn_lock: error %d incompatible with flags %#x", error, flags));
1576 if ((flags & LK_RETRY) == 0) {
1577 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0) {
1581 } else if (error != 0)
1587 * File table vnode close routine.
1590 vn_closefile(struct file *fp, struct thread *td)
1598 fp->f_ops = &badfileops;
1599 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE;
1601 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref);
1603 if (__predict_false(ref)) {
1604 lf.l_whence = SEEK_SET;
1607 lf.l_type = F_UNLCK;
1608 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1615 vn_suspendable(struct mount *mp)
1618 return (mp->mnt_op->vfs_susp_clean != NULL);
1622 * Preparing to start a filesystem write operation. If the operation is
1623 * permitted, then we bump the count of operations in progress and
1624 * proceed. If a suspend request is in progress, we wait until the
1625 * suspension is over, and then proceed.
1628 vn_start_write_refed(struct mount *mp, int flags, bool mplocked)
1632 if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 &&
1633 vfs_op_thread_enter(mp)) {
1634 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1635 vfs_mp_count_add_pcpu(mp, writeopcount, 1);
1636 vfs_op_thread_exit(mp);
1641 mtx_assert(MNT_MTX(mp), MA_OWNED);
1648 * Check on status of suspension.
1650 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1651 mp->mnt_susp_owner != curthread) {
1652 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1653 (flags & PCATCH) : 0) | (PUSER - 1);
1654 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1655 if (flags & V_NOWAIT) {
1656 error = EWOULDBLOCK;
1659 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1665 if (flags & V_XSLEEP)
1667 mp->mnt_writeopcount++;
1669 if (error != 0 || (flags & V_XSLEEP) != 0)
1676 vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
1681 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1682 ("V_MNTREF requires mp"));
1686 * If a vnode is provided, get and return the mount point that
1687 * to which it will write.
1690 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1692 if (error != EOPNOTSUPP)
1697 if ((mp = *mpp) == NULL)
1700 if (!vn_suspendable(mp)) {
1701 if (vp != NULL || (flags & V_MNTREF) != 0)
1707 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1709 * As long as a vnode is not provided we need to acquire a
1710 * refcount for the provided mountpoint too, in order to
1711 * emulate a vfs_ref().
1713 if (vp == NULL && (flags & V_MNTREF) == 0)
1716 return (vn_start_write_refed(mp, flags, false));
1720 * Secondary suspension. Used by operations such as vop_inactive
1721 * routines that are needed by the higher level functions. These
1722 * are allowed to proceed until all the higher level functions have
1723 * completed (indicated by mnt_writeopcount dropping to zero). At that
1724 * time, these operations are halted until the suspension is over.
1727 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
1732 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1733 ("V_MNTREF requires mp"));
1737 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1739 if (error != EOPNOTSUPP)
1745 * If we are not suspended or have not yet reached suspended
1746 * mode, then let the operation proceed.
1748 if ((mp = *mpp) == NULL)
1751 if (!vn_suspendable(mp)) {
1752 if (vp != NULL || (flags & V_MNTREF) != 0)
1758 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1760 * As long as a vnode is not provided we need to acquire a
1761 * refcount for the provided mountpoint too, in order to
1762 * emulate a vfs_ref().
1765 if (vp == NULL && (flags & V_MNTREF) == 0)
1767 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1768 mp->mnt_secondary_writes++;
1769 mp->mnt_secondary_accwrites++;
1773 if (flags & V_NOWAIT) {
1776 return (EWOULDBLOCK);
1779 * Wait for the suspension to finish.
1781 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1782 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
1791 * Filesystem write operation has completed. If we are suspending and this
1792 * operation is the last one, notify the suspender that the suspension is
1796 vn_finished_write(struct mount *mp)
1800 if (mp == NULL || !vn_suspendable(mp))
1803 if (vfs_op_thread_enter(mp)) {
1804 vfs_mp_count_sub_pcpu(mp, writeopcount, 1);
1805 vfs_mp_count_sub_pcpu(mp, ref, 1);
1806 vfs_op_thread_exit(mp);
1811 vfs_assert_mount_counters(mp);
1813 c = --mp->mnt_writeopcount;
1814 if (mp->mnt_vfs_ops == 0) {
1815 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1820 vfs_dump_mount_counters(mp);
1821 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0)
1822 wakeup(&mp->mnt_writeopcount);
1828 * Filesystem secondary write operation has completed. If we are
1829 * suspending and this operation is the last one, notify the suspender
1830 * that the suspension is now in effect.
1833 vn_finished_secondary_write(struct mount *mp)
1835 if (mp == NULL || !vn_suspendable(mp))
1839 mp->mnt_secondary_writes--;
1840 if (mp->mnt_secondary_writes < 0)
1841 panic("vn_finished_secondary_write: neg cnt");
1842 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1843 mp->mnt_secondary_writes <= 0)
1844 wakeup(&mp->mnt_secondary_writes);
1851 * Request a filesystem to suspend write operations.
1854 vfs_write_suspend(struct mount *mp, int flags)
1858 MPASS(vn_suspendable(mp));
1863 vfs_assert_mount_counters(mp);
1864 if (mp->mnt_susp_owner == curthread) {
1865 vfs_op_exit_locked(mp);
1869 while (mp->mnt_kern_flag & MNTK_SUSPEND)
1870 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
1873 * Unmount holds a write reference on the mount point. If we
1874 * own busy reference and drain for writers, we deadlock with
1875 * the reference draining in the unmount path. Callers of
1876 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
1877 * vfs_busy() reference is owned and caller is not in the
1880 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
1881 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
1882 vfs_op_exit_locked(mp);
1887 mp->mnt_kern_flag |= MNTK_SUSPEND;
1888 mp->mnt_susp_owner = curthread;
1889 if (mp->mnt_writeopcount > 0)
1890 (void) msleep(&mp->mnt_writeopcount,
1891 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
1894 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) {
1895 vfs_write_resume(mp, 0);
1902 * Request a filesystem to resume write operations.
1905 vfs_write_resume(struct mount *mp, int flags)
1908 MPASS(vn_suspendable(mp));
1911 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1912 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
1913 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
1915 mp->mnt_susp_owner = NULL;
1916 wakeup(&mp->mnt_writeopcount);
1917 wakeup(&mp->mnt_flag);
1918 curthread->td_pflags &= ~TDP_IGNSUSP;
1919 if ((flags & VR_START_WRITE) != 0) {
1921 mp->mnt_writeopcount++;
1924 if ((flags & VR_NO_SUSPCLR) == 0)
1927 } else if ((flags & VR_START_WRITE) != 0) {
1929 vn_start_write_refed(mp, 0, true);
1936 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
1940 vfs_write_suspend_umnt(struct mount *mp)
1944 MPASS(vn_suspendable(mp));
1945 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
1946 ("vfs_write_suspend_umnt: recursed"));
1948 /* dounmount() already called vn_start_write(). */
1950 vn_finished_write(mp);
1951 error = vfs_write_suspend(mp, 0);
1953 vn_start_write(NULL, &mp, V_WAIT);
1957 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
1960 vn_start_write(NULL, &mp, V_WAIT);
1962 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
1963 wakeup(&mp->mnt_flag);
1965 curthread->td_pflags |= TDP_IGNSUSP;
1970 * Implement kqueues for files by translating it to vnode operation.
1973 vn_kqfilter(struct file *fp, struct knote *kn)
1976 return (VOP_KQFILTER(fp->f_vnode, kn));
1980 * Simplified in-kernel wrapper calls for extended attribute access.
1981 * Both calls pass in a NULL credential, authorizing as "kernel" access.
1982 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
1985 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
1986 const char *attrname, int *buflen, char *buf, struct thread *td)
1992 iov.iov_len = *buflen;
1995 auio.uio_iov = &iov;
1996 auio.uio_iovcnt = 1;
1997 auio.uio_rw = UIO_READ;
1998 auio.uio_segflg = UIO_SYSSPACE;
2000 auio.uio_offset = 0;
2001 auio.uio_resid = *buflen;
2003 if ((ioflg & IO_NODELOCKED) == 0)
2004 vn_lock(vp, LK_SHARED | LK_RETRY);
2006 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2008 /* authorize attribute retrieval as kernel */
2009 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
2012 if ((ioflg & IO_NODELOCKED) == 0)
2016 *buflen = *buflen - auio.uio_resid;
2023 * XXX failure mode if partially written?
2026 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
2027 const char *attrname, int buflen, char *buf, struct thread *td)
2034 iov.iov_len = buflen;
2037 auio.uio_iov = &iov;
2038 auio.uio_iovcnt = 1;
2039 auio.uio_rw = UIO_WRITE;
2040 auio.uio_segflg = UIO_SYSSPACE;
2042 auio.uio_offset = 0;
2043 auio.uio_resid = buflen;
2045 if ((ioflg & IO_NODELOCKED) == 0) {
2046 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2048 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2051 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2053 /* authorize attribute setting as kernel */
2054 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
2056 if ((ioflg & IO_NODELOCKED) == 0) {
2057 vn_finished_write(mp);
2065 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
2066 const char *attrname, struct thread *td)
2071 if ((ioflg & IO_NODELOCKED) == 0) {
2072 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2074 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2077 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2079 /* authorize attribute removal as kernel */
2080 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2081 if (error == EOPNOTSUPP)
2082 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2085 if ((ioflg & IO_NODELOCKED) == 0) {
2086 vn_finished_write(mp);
2094 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2098 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2102 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2105 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2110 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2111 int lkflags, struct vnode **rvp)
2116 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2118 ltype = VOP_ISLOCKED(vp);
2119 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2120 ("vn_vget_ino: vp not locked"));
2121 error = vfs_busy(mp, MBF_NOWAIT);
2125 error = vfs_busy(mp, 0);
2126 vn_lock(vp, ltype | LK_RETRY);
2130 if (vp->v_iflag & VI_DOOMED) {
2136 error = alloc(mp, alloc_arg, lkflags, rvp);
2138 if (error != 0 || *rvp != vp)
2139 vn_lock(vp, ltype | LK_RETRY);
2140 if (vp->v_iflag & VI_DOOMED) {
2153 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2157 if (vp->v_type != VREG || td == NULL)
2159 if ((uoff_t)uio->uio_offset + uio->uio_resid >
2160 lim_cur(td, RLIMIT_FSIZE)) {
2161 PROC_LOCK(td->td_proc);
2162 kern_psignal(td->td_proc, SIGXFSZ);
2163 PROC_UNLOCK(td->td_proc);
2170 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2177 vn_lock(vp, LK_SHARED | LK_RETRY);
2178 AUDIT_ARG_VNODE1(vp);
2181 return (setfmode(td, active_cred, vp, mode));
2185 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2192 vn_lock(vp, LK_SHARED | LK_RETRY);
2193 AUDIT_ARG_VNODE1(vp);
2196 return (setfown(td, active_cred, vp, uid, gid));
2200 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2204 if ((object = vp->v_object) == NULL)
2206 VM_OBJECT_WLOCK(object);
2207 vm_object_page_remove(object, start, end, 0);
2208 VM_OBJECT_WUNLOCK(object);
2212 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2220 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2221 ("Wrong command %lu", cmd));
2223 if (vn_lock(vp, LK_SHARED) != 0)
2225 if (vp->v_type != VREG) {
2229 error = VOP_GETATTR(vp, &va, cred);
2233 if (noff >= va.va_size) {
2237 bsize = vp->v_mount->mnt_stat.f_iosize;
2238 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize -
2240 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2241 if (error == EOPNOTSUPP) {
2245 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2246 (bnp != -1 && cmd == FIOSEEKDATA)) {
2253 if (noff > va.va_size)
2255 /* noff == va.va_size. There is an implicit hole at the end of file. */
2256 if (cmd == FIOSEEKDATA)
2266 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2271 off_t foffset, size;
2274 cred = td->td_ucred;
2276 foffset = foffset_lock(fp, 0);
2277 noneg = (vp->v_type != VCHR);
2283 (offset > 0 && foffset > OFF_MAX - offset))) {
2290 vn_lock(vp, LK_SHARED | LK_RETRY);
2291 error = VOP_GETATTR(vp, &vattr, cred);
2297 * If the file references a disk device, then fetch
2298 * the media size and use that to determine the ending
2301 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2302 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2303 vattr.va_size = size;
2305 (vattr.va_size > OFF_MAX ||
2306 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2310 offset += vattr.va_size;
2315 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2316 if (error == ENOTTY)
2320 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2321 if (error == ENOTTY)
2327 if (error == 0 && noneg && offset < 0)
2331 VFS_KNOTE_UNLOCKED(vp, 0);
2332 td->td_uretoff.tdu_off = offset;
2334 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2339 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2345 * Grant permission if the caller is the owner of the file, or
2346 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2347 * on the file. If the time pointer is null, then write
2348 * permission on the file is also sufficient.
2350 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2351 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2352 * will be allowed to set the times [..] to the current
2355 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2356 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2357 error = VOP_ACCESS(vp, VWRITE, cred, td);
2362 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2367 if (fp->f_type == DTYPE_FIFO)
2368 kif->kf_type = KF_TYPE_FIFO;
2370 kif->kf_type = KF_TYPE_VNODE;
2373 FILEDESC_SUNLOCK(fdp);
2374 error = vn_fill_kinfo_vnode(vp, kif);
2376 FILEDESC_SLOCK(fdp);
2381 vn_fill_junk(struct kinfo_file *kif)
2386 * Simulate vn_fullpath returning changing values for a given
2387 * vp during e.g. coredump.
2389 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1;
2390 olen = strlen(kif->kf_path);
2392 strcpy(&kif->kf_path[len - 1], "$");
2394 for (; olen < len; olen++)
2395 strcpy(&kif->kf_path[olen], "A");
2399 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2402 char *fullpath, *freepath;
2405 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type);
2408 error = vn_fullpath(curthread, vp, &fullpath, &freepath);
2410 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2412 if (freepath != NULL)
2413 free(freepath, M_TEMP);
2415 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path,
2420 * Retrieve vnode attributes.
2422 va.va_fsid = VNOVAL;
2424 vn_lock(vp, LK_SHARED | LK_RETRY);
2425 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2429 if (va.va_fsid != VNOVAL)
2430 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2432 kif->kf_un.kf_file.kf_file_fsid =
2433 vp->v_mount->mnt_stat.f_fsid.val[0];
2434 kif->kf_un.kf_file.kf_file_fsid_freebsd11 =
2435 kif->kf_un.kf_file.kf_file_fsid; /* truncate */
2436 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2437 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2438 kif->kf_un.kf_file.kf_file_size = va.va_size;
2439 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
2440 kif->kf_un.kf_file.kf_file_rdev_freebsd11 =
2441 kif->kf_un.kf_file.kf_file_rdev; /* truncate */
2446 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
2447 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
2451 struct pmckern_map_in pkm;
2457 boolean_t writecounted;
2460 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
2461 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
2463 * POSIX shared-memory objects are defined to have
2464 * kernel persistence, and are not defined to support
2465 * read(2)/write(2) -- or even open(2). Thus, we can
2466 * use MAP_ASYNC to trade on-disk coherence for speed.
2467 * The shm_open(3) library routine turns on the FPOSIXSHM
2468 * flag to request this behavior.
2470 if ((fp->f_flag & FPOSIXSHM) != 0)
2471 flags |= MAP_NOSYNC;
2476 * Ensure that file and memory protections are
2477 * compatible. Note that we only worry about
2478 * writability if mapping is shared; in this case,
2479 * current and max prot are dictated by the open file.
2480 * XXX use the vnode instead? Problem is: what
2481 * credentials do we use for determination? What if
2482 * proc does a setuid?
2485 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
2486 maxprot = VM_PROT_NONE;
2487 if ((prot & VM_PROT_EXECUTE) != 0)
2490 maxprot = VM_PROT_EXECUTE;
2491 if ((fp->f_flag & FREAD) != 0)
2492 maxprot |= VM_PROT_READ;
2493 else if ((prot & VM_PROT_READ) != 0)
2497 * If we are sharing potential changes via MAP_SHARED and we
2498 * are trying to get write permission although we opened it
2499 * without asking for it, bail out.
2501 if ((flags & MAP_SHARED) != 0) {
2502 if ((fp->f_flag & FWRITE) != 0)
2503 maxprot |= VM_PROT_WRITE;
2504 else if ((prot & VM_PROT_WRITE) != 0)
2507 maxprot |= VM_PROT_WRITE;
2508 cap_maxprot |= VM_PROT_WRITE;
2510 maxprot &= cap_maxprot;
2513 * For regular files and shared memory, POSIX requires that
2514 * the value of foff be a legitimate offset within the data
2515 * object. In particular, negative offsets are invalid.
2516 * Blocking negative offsets and overflows here avoids
2517 * possible wraparound or user-level access into reserved
2518 * ranges of the data object later. In contrast, POSIX does
2519 * not dictate how offsets are used by device drivers, so in
2520 * the case of a device mapping a negative offset is passed
2527 foff < 0 || foff > OFF_MAX - size)
2530 writecounted = FALSE;
2531 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp,
2532 &foff, &object, &writecounted);
2535 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
2536 foff, writecounted, td);
2539 * If this mapping was accounted for in the vnode's
2540 * writecount, then undo that now.
2543 vm_pager_release_writecount(object, 0, size);
2544 vm_object_deallocate(object);
2547 /* Inform hwpmc(4) if an executable is being mapped. */
2548 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) {
2549 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) {
2551 pkm.pm_address = (uintptr_t) *addr;
2552 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm);
2560 vn_fsid(struct vnode *vp, struct vattr *va)
2564 f = &vp->v_mount->mnt_stat.f_fsid;
2565 va->va_fsid = (uint32_t)f->val[1];
2566 va->va_fsid <<= sizeof(f->val[1]) * NBBY;
2567 va->va_fsid += (uint32_t)f->val[0];
2571 vn_fsync_buf(struct vnode *vp, int waitfor)
2573 struct buf *bp, *nbp;
2576 int error, maxretry;
2579 maxretry = 10000; /* large, arbitrarily chosen */
2581 if (vp->v_type == VCHR) {
2583 mp = vp->v_rdev->si_mountpt;
2590 * MARK/SCAN initialization to avoid infinite loops.
2592 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
2593 bp->b_vflags &= ~BV_SCANNED;
2598 * Flush all dirty buffers associated with a vnode.
2601 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2602 if ((bp->b_vflags & BV_SCANNED) != 0)
2604 bp->b_vflags |= BV_SCANNED;
2605 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
2606 if (waitfor != MNT_WAIT)
2609 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
2610 BO_LOCKPTR(bo)) != 0) {
2617 KASSERT(bp->b_bufobj == bo,
2618 ("bp %p wrong b_bufobj %p should be %p",
2619 bp, bp->b_bufobj, bo));
2620 if ((bp->b_flags & B_DELWRI) == 0)
2621 panic("fsync: not dirty");
2622 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
2628 if (maxretry < 1000)
2629 pause("dirty", hz < 1000 ? 1 : hz / 1000);
2635 * If synchronous the caller expects us to completely resolve all
2636 * dirty buffers in the system. Wait for in-progress I/O to
2637 * complete (which could include background bitmap writes), then
2638 * retry if dirty blocks still exist.
2640 if (waitfor == MNT_WAIT) {
2641 bufobj_wwait(bo, 0, 0);
2642 if (bo->bo_dirty.bv_cnt > 0) {
2644 * If we are unable to write any of these buffers
2645 * then we fail now rather than trying endlessly
2646 * to write them out.
2648 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
2649 if ((error = bp->b_error) != 0)
2651 if ((mp != NULL && mp->mnt_secondary_writes > 0) ||
2652 (error == 0 && --maxretry >= 0))
2660 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error);
2666 * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE()
2667 * or vn_generic_copy_file_range() after rangelocking the byte ranges,
2668 * to do the actual copy.
2669 * vn_generic_copy_file_range() is factored out, so it can be called
2670 * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from
2671 * different file systems.
2674 vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp,
2675 off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred,
2676 struct ucred *outcred, struct thread *fsize_td)
2681 uint64_t uvalin, uvalout;
2684 *lenp = 0; /* For error returns. */
2687 /* Do some sanity checks on the arguments. */
2692 if (invp->v_type == VDIR || outvp->v_type == VDIR)
2694 else if (*inoffp < 0 || uvalin > INT64_MAX || uvalin <
2695 (uint64_t)*inoffp || *outoffp < 0 || uvalout > INT64_MAX ||
2696 uvalout < (uint64_t)*outoffp || invp->v_type != VREG ||
2697 outvp->v_type != VREG)
2699 else if (invp == outvp)
2704 error = vn_lock(invp, LK_SHARED);
2707 /* Check that the offset + len does not go past EOF of invp. */
2708 error = VOP_GETATTR(invp, &va, incred);
2709 if (error == 0 && va.va_size < *inoffp + len)
2711 VOP_UNLOCK(invp, 0);
2716 * If the two vnode are for the same file system, call
2717 * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range()
2718 * which can handle copies across multiple file systems.
2721 if (invp->v_mount == outvp->v_mount)
2722 error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp,
2723 lenp, flags, incred, outcred, fsize_td);
2725 error = vn_generic_copy_file_range(invp, inoffp, outvp,
2726 outoffp, lenp, flags, incred, outcred, fsize_td);
2732 * Test len bytes of data starting at dat for all bytes == 0.
2733 * Return true if all bytes are zero, false otherwise.
2734 * Expects dat to be well aligned.
2737 mem_iszero(void *dat, int len)
2743 for (p = dat; len > 0; len -= sizeof(*p), p++) {
2744 if (len >= sizeof(*p)) {
2748 cp = (const char *)p;
2749 for (i = 0; i < len; i++, cp++)
2758 * Look for a hole in the output file and, if found, adjust *outoffp
2759 * and *xferp to skip past the hole.
2760 * *xferp is the entire hole length to be written and xfer2 is how many bytes
2761 * to be written as 0's upon return.
2764 vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp,
2765 off_t *dataoffp, off_t *holeoffp, struct ucred *cred)
2770 if (*holeoffp == 0 || *holeoffp <= *outoffp) {
2771 *dataoffp = *outoffp;
2772 error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred,
2775 *holeoffp = *dataoffp;
2776 error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred,
2779 if (error != 0 || *holeoffp == *dataoffp) {
2781 * Since outvp is unlocked, it may be possible for
2782 * another thread to do a truncate(), lseek(), write()
2783 * creating a hole at startoff between the above
2784 * VOP_IOCTL() calls, if the other thread does not do
2786 * If that happens, *holeoffp == *dataoffp and finding
2787 * the hole has failed, so disable vn_skip_hole().
2789 *holeoffp = -1; /* Disable use of vn_skip_hole(). */
2792 KASSERT(*dataoffp >= *outoffp,
2793 ("vn_skip_hole: dataoff=%jd < outoff=%jd",
2794 (intmax_t)*dataoffp, (intmax_t)*outoffp));
2795 KASSERT(*holeoffp > *dataoffp,
2796 ("vn_skip_hole: holeoff=%jd <= dataoff=%jd",
2797 (intmax_t)*holeoffp, (intmax_t)*dataoffp));
2801 * If there is a hole before the data starts, advance *outoffp and
2802 * *xferp past the hole.
2804 if (*dataoffp > *outoffp) {
2805 delta = *dataoffp - *outoffp;
2806 if (delta >= *xferp) {
2807 /* Entire *xferp is a hole. */
2814 xfer2 = MIN(xfer2, *xferp);
2818 * If a hole starts before the end of this xfer2, reduce this xfer2 so
2819 * that the write ends at the start of the hole.
2820 * *holeoffp should always be greater than *outoffp, but for the
2821 * non-INVARIANTS case, check this to make sure xfer2 remains a sane
2824 if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2)
2825 xfer2 = *holeoffp - *outoffp;
2830 * Write an xfer sized chunk to outvp in blksize blocks from dat.
2831 * dat is a maximum of blksize in length and can be written repeatedly in
2833 * If growfile == true, just grow the file via vn_truncate_locked() instead
2834 * of doing actual writes.
2835 * If checkhole == true, a hole is being punched, so skip over any hole
2836 * already in the output file.
2839 vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer,
2840 u_long blksize, bool growfile, bool checkhole, struct ucred *cred)
2843 off_t dataoff, holeoff, xfer2;
2847 * Loop around doing writes of blksize until write has been completed.
2848 * Lock/unlock on each loop iteration so that a bwillwrite() can be
2849 * done for each iteration, since the xfer argument can be very
2850 * large if there is a large hole to punch in the output file.
2855 xfer2 = MIN(xfer, blksize);
2858 * Punching a hole. Skip writing if there is
2859 * already a hole in the output file.
2861 xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer,
2862 &dataoff, &holeoff, cred);
2867 KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd",
2872 error = vn_start_write(outvp, &mp, V_WAIT);
2874 if (MNT_SHARED_WRITES(mp))
2877 lckf = LK_EXCLUSIVE;
2878 error = vn_lock(outvp, lckf);
2882 error = vn_truncate_locked(outvp, outoff + xfer,
2885 error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2,
2886 outoff, UIO_SYSSPACE, IO_NODELOCKED,
2887 curthread->td_ucred, cred, NULL, curthread);
2891 VOP_UNLOCK(outvp, 0);
2894 vn_finished_write(mp);
2895 } while (!growfile && xfer > 0 && error == 0);
2900 * Copy a byte range of one file to another. This function can handle the
2901 * case where invp and outvp are on different file systems.
2902 * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there
2903 * is no better file system specific way to do it.
2906 vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp,
2907 struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags,
2908 struct ucred *incred, struct ucred *outcred, struct thread *fsize_td)
2913 off_t startoff, endoff, xfer, xfer2;
2916 bool cantseek, readzeros;
2918 size_t copylen, len, savlen;
2920 long holein, holeout;
2922 holein = holeout = 0;
2923 savlen = len = *lenp;
2927 error = vn_lock(invp, LK_SHARED);
2930 if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0)
2932 VOP_UNLOCK(invp, 0);
2935 error = vn_start_write(outvp, &mp, V_WAIT);
2937 error = vn_lock(outvp, LK_EXCLUSIVE);
2940 * If fsize_td != NULL, do a vn_rlimit_fsize() call,
2941 * now that outvp is locked.
2943 if (fsize_td != NULL) {
2944 io.uio_offset = *outoffp;
2946 error = vn_rlimit_fsize(outvp, &io, fsize_td);
2950 if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0)
2953 * Holes that are past EOF do not need to be written as a block
2954 * of zero bytes. So, truncate the output file as far as
2955 * possible and then use va.va_size to decide if writing 0
2956 * bytes is necessary in the loop below.
2959 error = VOP_GETATTR(outvp, &va, outcred);
2960 if (error == 0 && va.va_size > *outoffp && va.va_size <=
2963 error = mac_vnode_check_write(curthread->td_ucred,
2967 error = vn_truncate_locked(outvp, *outoffp,
2970 va.va_size = *outoffp;
2972 VOP_UNLOCK(outvp, 0);
2975 vn_finished_write(mp);
2980 * Set the blksize to the larger of the hole sizes for invp and outvp.
2981 * If hole sizes aren't available, set the blksize to the larger
2982 * f_iosize of invp and outvp.
2983 * This code expects the hole sizes and f_iosizes to be powers of 2.
2984 * This value is clipped at 4Kbytes and 1Mbyte.
2986 blksize = MAX(holein, holeout);
2988 blksize = MAX(invp->v_mount->mnt_stat.f_iosize,
2989 outvp->v_mount->mnt_stat.f_iosize);
2992 else if (blksize > 1024 * 1024)
2993 blksize = 1024 * 1024;
2994 dat = malloc(blksize, M_TEMP, M_WAITOK);
2997 * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA
2998 * to find holes. Otherwise, just scan the read block for all 0s
2999 * in the inner loop where the data copying is done.
3000 * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may
3001 * support holes on the server, but do not support FIOSEEKHOLE.
3003 while (len > 0 && error == 0) {
3004 endoff = 0; /* To shut up compilers. */
3010 * Find the next data area. If there is just a hole to EOF,
3011 * FIOSEEKDATA should fail and then we drop down into the
3012 * inner loop and create the hole on the outvp file.
3013 * (I do not know if any file system will report a hole to
3014 * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA
3015 * will fail for those file systems.)
3017 * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE,
3018 * the code just falls through to the inner copy loop.
3022 error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0,
3026 error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0,
3029 * Since invp is unlocked, it may be possible for
3030 * another thread to do a truncate(), lseek(), write()
3031 * creating a hole at startoff between the above
3032 * VOP_IOCTL() calls, if the other thread does not do
3034 * If that happens, startoff == endoff and finding
3035 * the hole has failed, so set an error.
3037 if (error == 0 && startoff == endoff)
3038 error = EINVAL; /* Any error. Reset to 0. */
3041 if (startoff > *inoffp) {
3042 /* Found hole before data block. */
3043 xfer = MIN(startoff - *inoffp, len);
3044 if (*outoffp < va.va_size) {
3045 /* Must write 0s to punch hole. */
3046 xfer2 = MIN(va.va_size - *outoffp,
3048 memset(dat, 0, MIN(xfer2, blksize));
3049 error = vn_write_outvp(outvp, dat,
3050 *outoffp, xfer2, blksize, false,
3051 holeout > 0, outcred);
3054 if (error == 0 && *outoffp + xfer >
3055 va.va_size && xfer == len)
3056 /* Grow last block. */
3057 error = vn_write_outvp(outvp, dat,
3058 *outoffp, xfer, blksize, true,
3066 copylen = MIN(len, endoff - startoff);
3078 * Set first xfer to end at a block boundary, so that
3079 * holes are more likely detected in the loop below via
3080 * the for all bytes 0 method.
3082 xfer -= (*inoffp % blksize);
3084 /* Loop copying the data block. */
3085 while (copylen > 0 && error == 0) {
3088 error = vn_lock(invp, LK_SHARED);
3091 error = vn_rdwr(UIO_READ, invp, dat, xfer,
3092 startoff, UIO_SYSSPACE, IO_NODELOCKED,
3093 curthread->td_ucred, incred, &aresid,
3095 VOP_UNLOCK(invp, 0);
3097 * Linux considers a range that exceeds EOF to
3098 * be an error, so we will too.
3100 if (error == 0 && aresid > 0)
3104 * Skip the write for holes past the initial EOF
3105 * of the output file, unless this is the last
3106 * write of the output file at EOF.
3108 readzeros = cantseek ? mem_iszero(dat, xfer) :
3110 if (!cantseek || *outoffp < va.va_size ||
3111 xfer == len || !readzeros)
3112 error = vn_write_outvp(outvp, dat,
3113 *outoffp, xfer, blksize,
3114 readzeros && xfer == len &&
3115 *outoffp >= va.va_size, false,
3129 *lenp = savlen - len;